Measurement concepts for new, highly integrated antennas

本提案是高集成度天线测量技术概念DFG项目的后续应用。该项目的主要重点是深入分析测量概念和可实现的测量精度，以表征100 GHz至300 GHz的集成天线。最小的传感器尺寸和大的可用绝对带宽导致了对毫米波范围内集成传感器的高度研究兴趣。然而，所需要的集成天线的特性是具有挑战性的，因为小的结构尺寸和短波长需要复杂的测量设置。由于芯片尺寸小，用于馈电天线的接触装置位于AUT的直接周围，通常比被测设备本身大得多。这导致了较大的系统测量误差。通过对设置进行彻底的误差分析，测量精度大大提高后，现在将详细分析剩余的误差机制，如晶圆探头反射或与键合线和封装的相互作用。首先，将天线所需要的直接辐射与不需要的反射分离，得到隔离天线的辐射场。通过将由此过滤的场与原始测量值进行比较，可以更好地了解发生的误差机制和相互作用。为此采用了两种算法，即MARS算法和源重构算法。然而，由于晶圆探头的强烈反射，确定键合线和封装的影响可能很困难。因此，实现了一种新的测量方法，允许由芯片上直接产生的信号馈送AUT的相位测量，而不是通过外部源的晶圆探头提供的信号。测量数据的后处理还可以使用价格较低的标准探头对集成天线进行表征。到目前为止，只有在使用针对天线测量进行优化的晶圆探头时，才能对集成天线进行精确测量。标准探头后信号的反射和阴影会导致较大的测量误差，从而抑制有意义的测量。因此，采用后处理算法重建实际辐射方向图，定位探头反射中心。天线的精度可以通过天线的增益和指向性来计算。目前，集成天线增益测量中的误差限制了效率测定的精度。为了提高测量效率，对增益比较测量中出现的误差进行了详细的分析。

This proposal is a subsequent application to the DFG project with the topic Measurement Technique Concepts for Highly Integrated Antennas. The main focus of the project were in-depth analyses of measurement concepts and of the achievable measurement accuracy for the characterization of integrated antennas from 100 GHz to 300 GHz.Minimal sensor sizes and large available absolute bandwidths lead to a high research interest towards integrated sensors in the millimeter wave range. However, the characterization of the required integrated antennas is challenging, as the small structure sizes and the short wavelengths require elaborate measurement setups. Due to the small chip dimensions the contacting fixtures, which are used to feed the antenna, are in the immediate surrounding of the AUT and are usually much bigger than the device under test itself. This leads to large systematic measurement errors. After the measurement accuracy has been improved considerably through a thorough error analysis of the setup, the remaining error mechanisms, like wafer probe reflections or interaction with bond wires and the packages, are now to be analyzed in detail. First, the desired direct radiation from the antenna is separated from the unwanted reflections to obtain the radiated field of the isolated antenna. By comparing the thereby filtered fields to the original measurements, a better understanding of the occurring error mechanisms and interactions can then be obtained. Two algorithms are employed for this, namely MARS and source reconstruction.Identifying the influence of bond wires and package can, however, be difficult due to the strong reflections from the wafer probe. Therefore, a new measurement method is realized to allow phase measurements of an AUT that is fed by a signal generated directly on the chip, instead of a signal supplied through a wafer probe from an external source.Post processing of the measurement data can also allow the characterization of integrated antennas with lower-priced standard probes. Until now accurate measurements of integrated antennas are only possible when wafer probes are used that are optimized for antenna measurements. Reflections and shadowing of the signal behind standard probes cause large measurement errors that inhibit meaningful measurements. Therefore, the post processing algorithms are used to reconstruct the actual radiation pattern and to locate the reflection centers of the probe.The accuracy of antennas can be calculated with gain and directivity of an antenna. So far the accuracy of the determined efficiency is limited by errors in the integrated antenna gain measurement. In order to improve efficiency measurements, a detailed analysis of errors, which occur in gain comparison measurements, is conducted.